Enum Attached Files
Above snippet demonstrate how to enumerate files openned by running programs on Windows.
Some file unlocker use that technique to find where a specific file is attached and then force processes using that file to release it handle (via code injection techniques). I will write an example in a future snippet thread.
Notice: At the bottom of that page, you will see a concreate example about how to use that unit.
Features
- Support both 32 and 64bit process.
- Doesn't require any additional libraries than native Delphi libraries.
- Support scanning : All process ; Single process; List of process.
Code
////////////////////////////////////////////////////////////////////////////////
// //
// Author: //
// -> Jean-Pierre LESUEUR (@DarkCoderSc) //
// https://github.com/DarkCoderSc //
// https://gist.github.com/DarkCoderSc //
// https://www.phrozen.io/ //
// License: //
// -> MIT //
// //
////////////////////////////////////////////////////////////////////////////////
unit UntEnumAttachedFiles;
interface
{$ALIGN ON}
{$MINENUMSIZE 4}
uses Windows, Classes, SysUtils, Generics.Collections, tlHelp32;
type
TSystemHandleInformation = record
ProcessId: ULONG;
ObjectTypeNumber: UCHAR;
Flags: UCHAR;
Handle: USHORT;
Object_: PVOID;
GrantedAccess: ACCESS_MASK;
end;
PSystemHandleInformation = ^TSystemHandleInformation;
TSystemHandleInformations = record
HandleCount : ULONG;
Handles : array[0..0] of TSystemHandleInformation;
end;
PSystemHandleInformations = ^TSystemHandleInformations;
TUnicodeString = record
Length: USHORT;
MaximumLength: USHORT;
Buffer: PWideChar;
end;
OBJECT_TYPE_INFORMATION = record
Name: TUnicodeString;
ObjectCount: ULONG;
HandleCount: ULONG;
Reserved1: array[0..3] of ULONG;
PeakObjectCount: ULONG;
PeakHandleCount: ULONG;
Reserved2: array[0..3] of ULONG;
InvalidAttributes: ULONG;
GenericMapping: GENERIC_MAPPING;
ValidAccess: ULONG;
Unknown: UCHAR;
MaintainHandleDatabase: ByteBool;
Reserved3: array[0..1] of UCHAR;
PoolType: Byte;
PagedPoolUsage: ULONG;
NonPagedPoolUsage: ULONG;
end;
POBJECT_TYPE_INFORMATION = ^OBJECT_TYPE_INFORMATION;
OBJECT_NAME_INFORMATION = record
Name: TUnicodeString;
end;
POBJECT_NAME_INFORMATION = ^OBJECT_NAME_INFORMATION;
type
TFileInfo = class
private
FFileName : String;
FHandle : THandle;
FFileSize : Int64;
{@M}
procedure SetFileName(AValue : String);
public
{@C}
constructor Create();
{@G/S}
property FileName : String read FFileName write SetFileName;
property Handle : THandle read FHandle write FHandle;
{@G}
property FileSize : Int64 read FFileSize;
end;
TEnumAttachedFiles = class
private
FItems : TObjectDictionary>;
FNTDLL : THandle; // Required Library
// https://docs.microsoft.com/en-us/windows/win32/api/winternl/nf-winternl-ntquerysysteminformation
NtQuerySystemInformation : function (
SystemInformationClass : Cardinal;
SystemInformation : PVOID;
SystemInformationLength : ULONG;
ReturnLength : PULONG): ULONG; stdcall;
// https://docs.microsoft.com/en-us/windows/win32/api/winternl/nf-winternl-ntqueryobject
NtQueryObject : function (
ObjectHandle : THandle;
ObjectInformationClass : Cardinal;
ObjectInformation : PVOID;
ObjectInformationLength : ULONG;
ReturnLength : PULONG
): ULONG; stdcall;
// https://undocumented.ntinternals.net/index.html?page=UserMode%2FUndocumented%20Functions%2FNT%20Objects%2FType%20independed%2FNtDuplicateObject.html
NtDuplicateObject : function (
SourceProcessHandle : THandle;
SourceHandle : THandle;
TargetProcessHandle : THandle;
TargetHandle : PHANDLE;
DesiredAccess : ACCESS_MASK;
Attributes : ULONG;
Options : ULONG
): ULONG; stdcall;
{@M}
function ReadHandleInformationByProcessBundle(AProcessId : Cardinal; var AHandles : TList) : TObjectList;
function EnumProcess(AFilterSameArch : Boolean = False) : TList;
function GetCount() : Cardinal;
public
{@C}
constructor Create();
destructor Destroy(); override;
{@M}
function Enum(AProcessList : TList) : Integer; overload;
function Enum(AProcessId : Cardinal) : Boolean; overload;
function Enum() : Integer; overload;
{@G}
property Items : TObjectDictionary> read FItems;
property TotalCount : Cardinal read GetCount;
end;
implementation
{+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
___Local___
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++}
function GetFileSize(AFileName : String) : Int64;
var AFileInfo : TWin32FileAttributeData;
begin
result := 0;
if NOT FileExists(AFileName) then begin
exit;
end;
if NOT GetFileAttributesEx(PWideChar(AFileName), GetFileExInfoStandard, @AFileInfo) then begin
exit;
end;
///
result := Int64(AFileInfo.nFileSizeLow) or Int64(AFileInfo.nFileSizeHigh shl 32);
end;
function IsProcessX64(AProcessId : Cardinal) : Boolean;
var AProcHandle : THandle;
AWow64Process : bool;
const PROCESS_QUERY_LIMITED_INFORMATION = $1000;
begin
result := false;
///
{
If we are not in a 64Bit system then we are for sure in a 32Bit system
}
if (TOSVersion.Architecture = arIntelX86) then
Exit();
///
AProcHandle := OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION, False, AProcessId);
if AProcHandle = 0 then
Exit;
try
isWow64Process(AProcHandle, AWow64Process);
///
result := (NOT AWow64Process);
finally
CloseHandle(AProcHandle);
end;
end;
function PhysicalToVirtualPath(APath : String) : String;
var i : integer;
ADrive : String;
ABuffer : array[0..MAX_PATH-1] of Char;
ACandidate : String;
begin
{$I-}
for I := 0 to 25 do begin
ADrive := Format('%s:', [Chr(Ord('A') + i)]);
///
if (QueryDosDevice(PWideChar(ADrive), ABuffer, MAX_PATH) = 0) then
continue;
ACandidate := String(ABuffer).ToLower();
if String(Copy(APath, 1, Length(ACandidate))).ToLower() = ACandidate then begin
Delete(APath, 1, Length(ACandidate));
result := Format('%s%s', [ADrive, APath]);
end;
end;
{$I+}
end;
{+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
TEnumAttachedFiles
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++}
{-------------------------------------------------------------------------------
___constructor
-------------------------------------------------------------------------------}
constructor TEnumAttachedFiles.Create();
begin
inherited Create();
///
FItems := TObjectDictionary>.Create([doOwnsValues]);
FNTDLL := LoadLibrary('NTDLL.DLL');
{
Acquire required API's from NTDLL.DLL
}
NtQuerySystemInformation := nil;
NtQueryObject := nil;
NtDuplicateObject := nil;
if (FNTDLL <> 0) then begin
@NtQuerySystemInformation := GetProcAddress(FNTDLL, 'NtQuerySystemInformation');
@NtQueryObject := GetProcAddress(FNTDLL, 'NtQueryObject');
@NtDuplicateObject := GetProcAddress(FNTDLL, 'NtDuplicateObject');
end;
end;
{-------------------------------------------------------------------------------
___destroy
-------------------------------------------------------------------------------}
destructor TEnumAttachedFiles.Destroy();
begin
if (FNTDLL <> 0) then
FreeLibrary(FNTDLL);
///
NtQuerySystemInformation := nil;
NtQueryObject := nil;
NtDuplicateObject := nil;
if Assigned(FItems) then
FreeAndNil(FItems);
///
inherited Destroy();
end;
{-------------------------------------------------------------------------------
Retrieve Information about each handles per owner process
-------------------------------------------------------------------------------}
function TEnumAttachedFiles.ReadHandleInformationByProcessBundle(AProcessId : Cardinal; var AHandles : TList) : TObjectList;
var i : integer;
AObjectHandle : THandle;
pObjectTypeInformation : POBJECT_TYPE_INFORMATION;
pObjectNameInformation : POBJECT_NAME_INFORMATION;
AObjectName : String;
ARet : Cardinal;
AProcessHandle : THandle;
AQueryHandle : THandle;
AFileInfo : TFileInfo;
ARequiredSize : DWORD;
AFileName : String;
begin
result := nil;
///
if NOT Assigned(AHandles) then
Exit();
AObjectHandle := 0;
AProcessHandle := OpenProcess(
(PROCESS_DUP_HANDLE or PROCESS_QUERY_INFORMATION or PROCESS_VM_READ),
False,
AProcessId
);
if (AProcessHandle = INVALID_HANDLE_VALUE) then
Exit();
try
result := TObjectList.Create(True);
///
for I := 0 to AHandles.Count -1 do begin
ARet := NTDuplicateObject(
AProcessHandle,
AHandles.Items[I], // Current Handle
GetCurrentProcess(),
@AObjectHandle,
0,
0,
0
);
if (ARet <> 0) then
Continue;
///
try
// Get Required Length before doing memory allocation
AQueryHandle := NtQueryObject(AObjectHandle, 2 {ObjectTypeInformation}, nil, 0, @ARequiredSize);
if (ARequiredSize <= 0) then
continue;
///
GetMem(pObjectTypeInformation, ARequiredSize);
try
{
Query Object Type
}
AQueryHandle := NtQueryObject(
AObjectHandle,
2 {ObjectTypeInformation},
pObjectTypeInformation,
ARequiredSize,
nil
);
if (AQueryHandle <> 0) then
Continue;
{
Filter for files handles only
}
if NOT String(pObjectTypeInformation^.Name.Buffer).ToUpper.StartsWith('FILE') then
continue;
finally
FreeMem(pObjectTypeInformation, ARequiredSize);
end;
{
Query Object Name (Should be Sizeof(TObjectNameInformation));
}
pObjectNameInformation := nil;
AQueryHandle := NTQueryObject(
AObjectHandle,
1 {ObjectNameInformation},
nil,
0,
@ARequiredSize
);
if (ARequiredSize <= 0) then
continue;
pObjectNameInformation := AllocMem(ARequiredSize);
try
AQueryHandle := NTQueryObject(
AObjectHandle,
1 {ObjectNameInformation},
pObjectNameInformation,
ARequiredSize,
NIL
);
if (AQueryHandle <> 0) then
Continue;
AObjectName := String(pObjectNameInformation^.Name.Buffer).Trim();
if (length(AObjectName) <= 0) then
Continue;
AFileName := PhysicalToVirtualPath(AObjectName);
if NOT FileExists(AFileName) then
continue;
{
Register new file information object
}
AFileInfo := TFileInfo.Create();
AFileInfo.FileName := AFileName;
AFileInfo.Handle := AHandles.Items[I];
{
Push
}
result.Add(AFileInfo);
finally
FreeMem(pObjectNameInformation, ARequiredSize);
end;
finally
CloseHandle(AObjectHandle);
end;
end;
finally
CloseHandle(AProcessHandle);
end;
end;
{-------------------------------------------------------------------------------
Enumerate Open Handles (Type = Open Files)
-------------------------------------------------------------------------------}
function TEnumAttachedFiles.Enum(AProcessList : TList) : Integer;
var AQueryHandle : THandle;
pHandleInformations : PSystemHandleInformations;
pCurrentHandleInformation : PSystemHandleInformation;
ARequiredSize : DWORD;
I : Integer;
ARet : Cardinal;
AHandles : TObjectDictionary>;
AHandleList : TList;
AFileInfoList : TObjectList;
const BASE_SIZE = 1024;
begin
result := -99; // Unknwon
///
self.FItems.Clear();
{
We must have access to those API's
}
if (NOT Assigned(NtQuerySystemInformation)) or
(NOT Assigned(NtQueryObject)) or
(NOT Assigned(NtDuplicateObject))
then
Exit();
///
ARequiredSize := 0;
ARequiredSize := BASE_SIZE;
pHandleInformations := AllocMem(ARequiredSize);
try
{
Retrieve open handles informations.
Notice: Between two NTQuerySystemInformation calls, required size could increase
resulting to another STATUS_INFO_LENGTH_MISMATCH error. Multiple NTQuerySystemInformation
call could be required until we succeed.
}
while true do begin
AQueryHandle := NTQuerySystemInformation(
16 {SystemHandleInformation},
pHandleInformations,
ARequiredSize,
@ARequiredSize
);
case AQueryHandle of
ULONG($C0000004) {STATUS_INFO_LENGTH_MISMATCH} : begin
ReallocMem(pHandleInformations, ARequiredSize);
end;
0 :
break;
else
Exit(-1);
end;
end;
{
Enumerate handle, and sort them by it owner process ID
}
AHandles := TObjectDictionary>.Create([doOwnsValues]);
try
for I := 0 to (pHandleInformations^.HandleCount -1) do begin
{$IFNDEF WIN64}
pCurrentHandleInformation := pointer(Integer(@pHandleInformations^.Handles) + (I * SizeOf(TSystemHandleInformation)));
{$ELSE}
pCurrentHandleInformation := pointer(Int64(@pHandleInformations^.Handles) + (I * SizeOf(TSystemHandleInformation)));
{$ENDIF}
{
Ignore out of scope processes
}
if NOT AProcessList.Contains(pCurrentHandleInformation.ProcessId) then
continue;
{
Filter some access value and file types which was identified as causing problems
}
ARet := GetFileType(pCurrentHandleInformation^.Handle);
if (ARet <> FILE_TYPE_DISK) and (ARet <> FILE_TYPE_UNKNOWN) then
Continue;
if (pCurrentHandleInformation^.GrantedAccess = $0012019F) or
(pCurrentHandleInformation^.GrantedAccess = $001A019F) or
(pCurrentHandleInformation^.GrantedAccess = $00120189) or
(pCurrentHandleInformation^.GrantedAccess = $00100000) then
continue;
AHandleList := nil;
if AHandles.ContainsKey(pCurrentHandleInformation^.ProcessId) then begin
if NOT AHandles.TryGetValue(pCurrentHandleInformation^.ProcessId, AHandleList) then
continue;
end else begin
AHandleList := TList.Create();
AHandles.Add(pCurrentHandleInformation^.ProcessId, AHandleList);
end;
if Assigned(AHandleList) then
AHandleList.Add(pCurrentHandleInformation^.Handle);
end;
{
Final Step is to retrieve additional information about each captured handle
per owner process ID
}
for I in AHandles.Keys do begin
if NOT AHandles.TryGetValue(I {Process ID}, AHandleList) then
continue;
///
AFileInfoList := ReadHandleInformationByProcessBundle(I, AHandleList);
if Assigned(AFileInfoList) then begin
if (AFileInfoList.Count > 0) then
FItems.Add(I, AFileInfoList);
end;
end;
///
result := 0; // Error Success
finally
if Assigned(AHandles) then
FreeAndNil(AHandles);
end;
finally
FreeMem(pHandleInformations, ARequiredSize);
end;
end;
{-------------------------------------------------------------------------------
Enumerate All Process for Open / Attached Files
-------------------------------------------------------------------------------}
function TEnumAttachedFiles.Enum() : Integer; // Result = Number of scanned Process
var AList : TList;
begin
AList := EnumProcess(True);
if Assigned(AList) then begin
try
if (AList.Count > 0) then
Enum(AList);
finally
FreeAndNil(AList);
end;
end;
end;
{-------------------------------------------------------------------------------
Enumerate a single process
-------------------------------------------------------------------------------}
function TEnumAttachedFiles.Enum(AProcessId : Cardinal) : Boolean;
var AList : TList;
begin
AList := TList.Create();
try
AList.Add(AProcessId);
result := (self.Enum(AList) = 0);
finally
if Assigned(AList) then
FreeAndNil(AList);
end;
end;
{-------------------------------------------------------------------------------
Get Total Attached Files Count
-------------------------------------------------------------------------------}
function TEnumAttachedFiles.GetCount() : Cardinal;
var AProcessId : Cardinal;
AFiles : TObjectList;
begin
result := 0;
///
for AProcessId in FItems.Keys do begin
if NOT FItems.TryGetValue(AProcessId, AFiles) then
continue;
///
if Assigned(AFiles) then
Inc(result, AFiles.Count);
end;
end;
{-------------------------------------------------------------------------------
Enumerate Running Process (Compatible for Enum(ProcessList))
-------------------------------------------------------------------------------}
function TEnumAttachedFiles.EnumProcess(AFilterSameArch : Boolean = False) : TList;
var ASnap : THandle;
AProcessEntry : TProcessEntry32;
AProcessName : String;
procedure AppendEntry();
begin
if AFilterSameArch and ((IsProcessX64(GetCurrentProcessId())) <> (IsProcessX64(AProcessEntry.th32ProcessID))) then
Exit();
// ///
result.Add(AProcessEntry.th32ProcessID);
end;
begin
result := TList.Create();
///
ASnap := CreateToolHelp32Snapshot(TH32CS_SNAPPROCESS, 0);
if ASnap = INVALID_HANDLE_VALUE then
Exit();
try
ZeroMemory(@AProcessEntry, SizeOf(TProcessEntry32));
///
AProcessEntry.dwSize := SizeOf(TProcessEntry32);
if NOT Process32First(ASnap, AProcessEntry) then
Exit();
AppendEntry();
while True do begin
ZeroMemory(@AProcessEntry, SizeOf(TProcessEntry32));
///
AProcessEntry.dwSize := SizeOf(TProcessEntry32);
if NOT Process32Next(ASnap, AProcessEntry) then
break;
AppendEntry();
end;
finally
CloseHandle(ASnap);
end;
end;
{+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
TFileInfo
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++}
constructor TFileInfo.Create();
begin
inherited Create();
///
FFileName := '';
FHandle := INVALID_HANDLE_VALUE;
FFileSize := 0;
end;
procedure TFileInfo.SetFileName(AValue: string);
begin
FFileName := AValue;
FFileSize := GetFileSize(AValue);
end;
end.
Usage Example (Console Application)
////////////////////////////////////////////////////////////////////////////////
// //
// Author: //
// -> Jean-Pierre LESUEUR (@DarkCoderSc) //
// https://github.com/DarkCoderSc //
// https://www.phrozen.io/ //
// License: //
// -> MIT //
// //
// Description: //
// -> Demonstrate how to use UntEnumAttachedFiles.pas //
// //
////////////////////////////////////////////////////////////////////////////////
program ListAttachedFiles;
{$APPTYPE CONSOLE}
{$R *.res}
uses
Windows, System.SysUtils, UntEnumAttachedFiles, Generics.Collections;
var AEnum : TEnumAttachedFiles;
AProcessId : Integer;
AFiles : TObjectList;
I : Integer;
AFileInfo : TFileInfo;
{-------------------------------------------------------------------------------
Get Process Name (>= Vista)
https://www.phrozen.io/snippets/2020/03/get-process-name-method-1-delphi/
-------------------------------------------------------------------------------}
function GetProcessName(AProcessID : Cardinal) : String;
var hProc : THandle;
ALength : DWORD;
hDLL : THandle;
QueryFullProcessImageNameW : function(
AProcess: THANDLE;
AFlags: DWORD;
AFileName: PWideChar;
var ASize: DWORD): BOOL; stdcall;
const PROCESS_QUERY_LIMITED_INFORMATION = $00001000;
begin
result := '';
///
if (TOSVersion.Major < 6) then
Exit();
///
QueryFullProcessImageNameW := nil;
hDLL := LoadLibrary('kernel32.dll');
if hDLL = 0 then
Exit();
try
@QueryFullProcessImageNameW := GetProcAddress(hDLL, 'QueryFullProcessImageNameW');
///
if Assigned(QueryFullProcessImageNameW) then begin
hProc := OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION, false, AProcessID);
if hProc = 0 then exit;
try
ALength := (MAX_PATH * 2);
SetLength(result, ALength);
if NOT QueryFullProcessImageNameW(hProc, 0, @result[1], ALength) then
Exit();
SetLength(result, ALength); // Get rid of extra junk
finally
CloseHandle(hProc);
end;
end;
finally
FreeLibrary(hDLL);
end;
end;
{-------------------------------------------------------------------------------
Display Program Help banner and optionally an error message.
-------------------------------------------------------------------------------}
procedure ShowHelp(AErrorMessage : String = '');
begin
if Length(AErrorMessage) > 0 then begin
WriteLn('');
WriteLn('Error: ' + AErrorMessage);
end;
WriteLn('');
WriteLn('Usage:');
WriteLn('-a : List all attached files (System Wide).');
WriteLn('-p : List all attached files from target process id.');
WriteLn('');
end;
begin
try
if (ParamCount <= 0) or (ParamCount > 2) then begin
raise Exception.Create('');
end else begin
AEnum := TEnumAttachedFiles.Create();
try
if (ParamCount = 1) and (ParamStr(1) = '-a') then
AEnum.Enum() // Enumerate All
else if (ParamStr(1) = '-p') then begin
if TryStrToInt(ParamStr(2), AProcessId) then
AEnum.Enum(AProcessId)
else
raise Exception.Create('Invalid Process Id (Must be numerical and >= 0).');
end else
raise Exception.Create('Invalid option.');
{
Display Grabbed Files
}
for AProcessId in AEnum.Items.Keys do begin
if NOT AEnum.Items.TryGetValue(AProcessId, AFiles) then
continue;
///
Writeln('----------------------------------------------------------');
Writeln(Format('%s (%d)', [ExtractFileName(GetProcessName(AProcessId)), AProcessId]));
Writeln(ExtractFilePath(GetProcessName(AProcessId)));
Writeln(Format('File Count : %d', [AFiles.Count]));
Writeln('----------------------------------------------------------');
for I := 0 to AFiles.Count -1 do begin
AFileInfo := AFiles.Items[I];
if NOT Assigned(AFileInfo) then
continue;
Writeln(Format('* [%s] %s', [IntToHex(AFileInfo.Handle, 8), AFileInfo.FileName]));
end;
Writeln('----------------------------------------------------------');
Writeln('');
end;
finally
if Assigned(AEnum) then
FreeAndNil(AEnum);
end;
end;
except
on E: Exception do
ShowHelp(E.Message);
end;
end.
How it looks like
Written the Nov. 23, 2020, 10:02 a.m. by Jean-Pierre LESUEUR
Updated: ago.